Apparatus for selectively alerting party line subscribers

Abstract From the Canadian patent

An apparatus is described having the capability to selectively alert subscribers in a telephone party line system where different subscriber parties are alerted using different ringing configurations. Subscribers are identified as being a member of a party by the connection pattern used to interface the apparatus to the telephone party line. The apparatus comprises means for detecting whether a ringer signal received from the telephone line is meant to alert a given subscriber party, and means for coupling the ringer signal to subscriber alerting equipment when an appropriate ringer signal is detected.